Ethanol is a sedative drug but it is not yet known how the sedative effects of ethanol are mediated in humans. One possible mechanism is that ethanol increases levels of the neuroactive steroid, allopregnanolone (allo-P). Allopregnanolone is a potent modulator of the GABA-A receptor. This study will investigate whether ethanol increases plasma levels of allopregnanolone in healthy young men and women. We predict that ethanol will increase levels of allo-P, and that these increases will correspond to subject ratings of sedation.